1. Field of the Invention
The present invention relates to an image transfer system including an image forming apparatus for forming an image and an external equipment communicably connected to the image forming apparatus, and the image forming apparatus for forming an image.
2. Description of the Related Art
Complex machines which are currently available in the market have various functions including a security function. The security function is a function for restricting a document reading operation and an outputting operation in accordance with a user who uses the complex machine. A document to be read may include information which is open to any person and information which should be read only by a certain person in a mixed manner. For example, Japanese Patent Unexamined Publication No. 2004-297758 (hereinafter, referred to as “conventional technology”) discloses an image processing apparatus. In the image processing apparatus, a color document including a secret part described in a specified color is read, and then a user authentication is performed. If the authentication is not completed, the specified color part of the read image data is erased so that an output of the specified color is aborted. Then, the image data from which the specified color part is erased is printed on a recording sheet.
Further, in the image processing apparatus according to the above-described conventional technology, the color image data is received and stored, and an addressee permitted to receive the specified color part of the received color image data is stored. If the addressee of the received color image data is not stored, the specified color part of the received color image data is extracted, and then transmission of the extracted specified color part is aborted.
As described above, according to the conventional technology described above, the specified color part is erased at a time of printing and transmitting data. Accordingly, inadvertent copying, printing, or facsimile transmission of a secret part of a document can be prevented.
However, according to the conventional technology, since color image data is sent after a specified color part is erased, it is necessary to transmit the color image data again if the person who receives the color image data will be allowed to refer to the secret part. Therefore, a convenience for a user was impaired.